The present invention relates to an agricultural mower having a cutting mechanism such as a reciprocating cutter bar or rotary cutter for mowing a crop and guiding the crop into conditioner rolls and thence through a windrower, if desired, for placing the cut, conditioned crop in a window for later pick up by a bailing machine.
Agricultural mowers of this type are widely used for harvesting varying kinds of crop, particularly hay and forage crops such as alfalfa. The mowers may either be self-propelled or adapted to be pulled by an agricultural tractor, as is the embodiment illustrated herein.
Moreover, there are variations in the types of equipment used for mowing. For example, not all mowers condition the crop, and not all mowers form the cut crop into a window. Some mowers simply leave the crop in a swath having substantially the same width as the cut swath. Thus, the embodiment disclosed herein of the cutting and conditioning mechanism is for exemplary purposes only and is not intended to limit the scope of the invention, as persons skilled in the art will readily appreciate.
In an effort to cut as much of the crop as possible for harvesting, the cutter mechanism, whether it is a reciprocating or a rotary-type cutting mechanism, is located close to the ground. Because at the time of harvest, the crop is usually comparatively high and thick, it is difficult to see obstructions such as rocks, stumps or partially buried logs. Should the cutting mechanism strike such an obstruction, it can not only cause damage to the individual cutting blade which strikes the obstacle; but since most cutting mechanisms are driven from a common source, a bent blade can have the effect of stopping the entire cutting mechanism or damaging a blade by causing breakage.
Thus, there have been attempts to reduce damage to the cutter guards in the case of a reciprocating cutter-bar mowing mechanism, for example. There have been other attempts to reduce damage to the cutting mechanism. One such attempt is disclosed in my U.S. Pat. No. 4,747,255 for CUTTER-BAR SUPPORT, issued May 31, 1988. In that patent, there is described a suspension system for a reciprocating cutter-bar assembly which includes a parallel linkage suspension mechanism on each side of the cutter-bar assembly. The suspension mechanism includes swing arms which, in the use position, are substantially vertically oriented and interconnect the mower main frame with a movable cutter bar assembly, enabling the cutter-bar assembly, should it strike an object, to respond by moving first primarily rearwardly relative to the direction of travel of the main frame, and then, in a pendulum-type movement, to elevate the cutter-bar assembly above the obstruction to clearing height. This mechanism enables the mower to travel at normal ground speeds while permitting the cutter-bar assembly to react quickly in the event an obstacle is encountered by moving primarily rearwardly and then upwardly.
In the case where the obstruction is high enough, it can have the effect of striking the reel assembly itself, thereby possibly damaging the reel. This is so even though the cutter-bar assembly may be moved upwardly to clear the obstacle. Thus, agricultural mowers have been proposed in which the reel is raised in correspondence with movement of the cutter-bar assembly. However, with significant movement of the reel assembly relative to the conditioning rollers, the flow path from the reel to the inlet of the conditioning rollers will be interrupted, resulting in blockage within the mower.